Home and office printers typically are used to print upon print media, such as paper and labels. Many printers, such as inkjet printers and thermal printers, employ the elements of a printhead and platen. Mechanical feed mechanisms feed a sheet of print media (such as paper, or a label or sheet of labels) between the printhead and the platen.
For many printers, a necessary component of the printing process is that pressure be applied by the printhead to the print media. The printhead presses on the print media, which is in turn supported by the platen.
For a print process to provide a consistent density of printing across the width of a print media, it is often desirable that the pressure on the print media should be consistent across the print media. Put another way, the pressure exerted on the print media by the printhead on one side of the media sheet, and the platen on the other side of the media sheet, should be consistent across the width of the media.
In some cases—for example, standard 8.5 inch by 11 inch paper fed through a typical office or home printer—the width of the print substantially spans the width of the printhead and the platen. In such cases, the printhead and the platen will tend to naturally exert a consistent level of pressure across the width of the print media.
Some print media, however, such as some labels fed through a printer, may not span the full width of the printhead and platen. If the labels span substantially less than the full width of the printhead/platen elements, the pressure across the print media may be uneven. In turn, if the pressure on the print media is uneven, the resulting print process may induce inconsistent levels of print on the media. That is, the print may be excessively dark towards one end of the print media and excessively light towards the other end of the print media.
What is needed, then, is a system and method for printing which identifies uneven pressure on a print media, and compensates for the uneven pressure, thereby ensuring consistent print density across the print media.